Transformation-associated changes in regulating cell growth and proliferation result in specific nutrient or
metabolic enzyme dependencies that are absent in non-transformed cells. Thus, nutrient dependency has
recently been shown to be therapeutically exploitable in cancer. On the other hand, cancer cells frequently face
nutrient limitation resulting from environmental variations, such as poor vascular supply, enhanced local
consumption, dietary restriction and response to therapeutics. As a result, cancer cells become increasingly
dependent on adaptive responses to mitigate metabolic stress. Therefore, defining the metabolites and the stress
response pathways on which cancer cells depend will facilitate development of better therapeutic strategies that
can improve management of cancer patients. For example, glutamine, a versatile biosynthetic substrate in
cancer cells, is frequently found depleted in tumor environment when compared to normal surrounding tissues.
We recently demonstrated that asparagine, a nonessential amino acid, plays a critical role in regulating tumor
cells' adaptation to glutamine depletion, raising the potential to target asparagine bioavailability to treat cancer.
However, little is known about how tumor cells sense and respond to asparagine deficiency. In this proposal, we
will use lymphoid malignancies as models to explore the role of adaptive amino acid response in tumor cells'
response to asparagine availability and its implication in cancer therapy. Our central hypothesis is that: neoplastic
lymphocytes rely on de novo biosynthesis to produce asparagine when environmental asparagine becomes
limiting. This adaptive program requires both the expression of key biosynthetic enzyme and the availability of
glutamine-derived biosynthetic substrates, which can collectively affect oncogenic signaling beyond their roles
in biosynthesis. Using biochemical, genetic and translational approaches, we will: (1) determine signaling and
chromatin-modifying components regulating cellular adaptation to asparagine deprivation in acute lymphoblastic
leukemia (ALL) and (2) determine impact of glutamine/asparagine metabolism on oncogenic MYC function in
ALL and MYC-driven B cell lymphoma.